Laser beam bender

ABSTRACT

A laser beam bender for changing the direction of a laser beam which includes a mirror holder having a spherical sliding surface having the reflection center of a reflection mirror as the center of curvature thereof is fixed on an L-shaped light guide member for guiding the laser beam. A mirror holding member holds the reflection mirror and has a sliding surface which slides on the sliding surface of the mirror holder. A micrometer moves the mirror holder in a lateral direction and causes the mirror holding member to slide. The reflection center of the reflection mirror remains stationary when the mirror holding member is slidably moved by the micrometer to adjust the reflection angle of the reflection mirror.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a laser beam bender used in a laser beammachine composed of a combination of an articulated robot and a laseroscillator, and now particularly, to a laser beam bender capable ofadjusting a reflection angle while the center of a reflection mirror isfixed.

2. Description of the Art

A laser beam machine composed of a combination of an articulated robotand a laser oscillator is widely used for metal welding or to effect aheat treatment process. With such a combination the positioningprecision by the robot is thereby enhanced and the laser beam machinecan be constructed by coupling a laser oscillator to a commerciallyavailable robot.

With this type of laser beam machine, it is necessary to guide a laserbeam along the arm of the robot from the laser oscillator to the wristof the robot, and accordingly, a laser beam bender for changing thedirection of the laser beam must be provided midway of the path thereof.

In such a laser beam bender, a mirror holder or the like on which areflection mirror is fixed is adjusted by using a micrometer or screw.In the laser beam benders now used, however, when the reflection angleof the mirror holder is adjusted by the micrometer, not only thereflection angle but also the mirror holder is moved linearly, and thusthe center of the reflection mirror is also moved. As a result, thecenter of the reflection mirror must be returned to the originalposition thereof after the reflection angle is adjusted, but thereflection angle is changed when the center of the reflection mirror isreturned to its original position, and therefore, the reflection anglemust be again adjusted, and this adjustment must be repeatedly effectedto finally obtain an accurate reflection angle.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a laser beam bendercapable of adjusting the reflection angle while the center of thereflection mirror is fixed.

The present invention achieves the above object by providing a laserbeam bender for changing the direction of a laser beam, the benderincluding "L-shaped" light guide member for guiding the laser beam; amirror holder fixed to the light guide member and having as an internalsurface a spherical sliding surface having the reflection center of areflection mirror as the center thereof; a mirror holding member forholding the reflection mirror and having a sliding surface able to slideon the sliding surface of the mirror holder; a micrometer or screw formoving the mirror holder member in a lateral direction; a first springfor applying a drag to the micrometer in the lateral direction; and asecond spring for applying a drag to the micrometer in a verticaldirection.

Since the mirror holding member holding the reflection mirror and themirror holder fixed on the light guide member are able to slide onspherical surfaces thereof having the reflection center of thereflection mirror as the centers thereof, the center of the reflectionmirror is not changed even if the mirror holding member is slidablymoved by the micrometer, thus making it possible to easily adjust onlythe reflection angle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing one embodiment of a laser beam bender accordingto this invention; and

FIG. 2 is a view of the laser beam bender along an arrow A in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings, shown in FIG. 1 is one embodiment of a laserbeam bender according to this invention. In FIG. 1, 1 denotes a mirrorholding member formed of, for example, brass. The mirror holding member1 holds a reflection mirror 3. Further, 3a denotes the reflection centerof the reflection mirror to which the center of the optical axis of alaser beam 13a is applied, and 2 denotes a mirror holder fixed on alight guide member 4. The light guide member 4 has an "L-shaped"configuration, and the laser beam 13a passes through one side of thelight guide member 4, is reflected at the reflection mirror 3, and thelaser beam 13b is then emitted from the other side of the light guidemember 4.

Numeral 5 denotes a micrometer which is rotated to cause a member 8 tobe moved via a sphere 7 mounted on the tip end of the micrometer, tothereby move the mirror holding member 1 in a lateral direction. Themirror holding member 1 is pressed in the lateral direction against asphere 9 mounted on a spring 10 and pressed in the vertical directionagainst a sphere 12 mounted on a spring 11.

The sliding surface 1a of the mirror holding member 1 is a sphericalsurface having the reflection center 3a of the reflection mirror 3 asthe center thereof, and a sliding surface 2a of the mirror holder 2 hasthe same configuration. Therefore, although an adjustment of themicrometer 5 causes the mirror holding member 1 to slide as indicated byan arrow B in FIG. 1, the reflection center 3a of the reflection mirror3 does not move, and therefore, an easy adjustment of only thereflection angle is possible. The preferred actual angle adjustment isin the range of ±2.5 degrees. No problem will arise, however if theangle adjustment is in the range of ±5 degrees.

In the above explanation, the angle is adjusted in a plane parallel tothe plane of FIG. 1, but the angle can be adjusted in the same manner ina plane perpendicular to the plane of FIG. 1.

FIG. 2 is a view of the laser beam bender along the arrow A of FIG. 1.The angle adjustment in the plane parallel to the plane of FIG. 1 iseffected by the micrometer 5, and the angle adjustment in a planeperpendicular to the plane of the Figure is effected by anothermicrometer 15. This permits the angle adjustment of the reflectionmirror 3 to be effected in a desired direction without moving thereflection center 3a, thus making it easier to effect the angleadjustment.

In the above explanation, the construction is such that the angle can beadjusted by using two micrometers, but it is possible to use aconstruction having three or more micrometers. Further, it is possibleto use a screw instead of the micrometer.

As described above, in this invention, since the mirror holding memberand the mirror holder are able to slide on spherical surfaces having thereflection center of the reflection mirror as the respective centers, itis possible to adjust only the reflection angle without moving thecenter of the reflection mirror, thereby making it easier to adjust theangle.

I claim:
 1. A laser beam bender for changing the direction of a laserbeam comprising:an L-shaped light guide member for guiding the laserbeam; a reflection mirror; a mirror holder fixed to the light guidemember, said mirror holder having as an internal surface a sphericalsliding surface having the reflection center of said reflection mirroras its center of curvature thereof; a mirror holding member for holdingsaid reflection mirror and having a sliding surface adapted to slide onthe sliding surface of said mirror holder; means for moving said mirrorholder member in a lateral direction; a first spring for applying dragin the lateral direction to said means for moving said mirror holdermember; and a sound spring for applying drag in a vertical direction tosaid means for moving said mirror holder member.
 2. A laser beam benderaccording to claim 1, wherein said means for moving said mirror holdermember includes at least two micrometers arranged at right angles toeach other.
 3. A laser beam bender according to claim 1, which includesa sliding sphere mounted on the tip end of each of said first and secondsprings.
 4. A laser beam bender according to claim 1, wherein saidsliding surface of said mirror holding member is spherical and has thereflection center of said reflection mirror as its center of curvaturethereof.
 5. A laser beam bender according to claim 1, wherein said meansfor moving said mirror holder member comprises a micrometer.